WASHINGTON — Senate Republicans unanimously named Sen. Mitch McConnell of Kentucky to serve as majority leader when the new Congress convenes in January. Democrats, meanwhile, elevated Sen. Elizabeth Warren, D-Mass., to a newly created seat at the leadership table as part of their efforts to renew the party's economic message.

McConnell's elevation was not in doubt after Republicans picked up at least eight seats in the midterm elections. A Louisiana Senate race heads to a Dec. 6 runoff where GOP Rep. Bill Cassidy is favored over Democratic Sen. Mary Landrieu. If he wins, McConnell will have a 54-seat majority next year.

Democrats re-elected Harry Reid of Nevada to lead their caucus, but also added new faces to their leadership team to include Warren and Sens. Amy Klobuchar of Minnesota, who is filling a slot held by Sen. Mark Begich, D-Alaska, who lost re-election. Klobuchar said she would work to "break through the gridlock" that defined the current Congress.

Warren is a popular figure among the party's progressive base, which had lackluster turnout on Election Day. Senate Democrats now have four women serving in a leadership team that also includes Sen. Patty Murray, D-Wash. and Sen. Debbie Stabenow, D-Mich.

Democrats are working to fine-tune an economic message that failed to inspire their voters in the midterms. Warren is a favorite of the party's liberal wing, which embraces her populist style and willingness to take on the banking and financial services industries.

"You know, Wall Street is doing very well, CEOs are bringing in millions more, and families all across this country are struggling. We have to make this government work for the American people, and that's what we're here to fight for," Warren said following Thursday's leadership elections.

At least six Democrats said publicly they did not support Reid's re-election following the loss of the Democratic majority. Voters "want change in Washington," Sen. Claire McCaskill, D-Mo., said in a statement. "Common sense tells me that begins with changes in leadership." Sens. Joe Manchin of West Virginia, Heidi Heitkamp of North Dakota, Mary Landrieu of Louisiana also voted against Reid. The Washington Post reported Virginia Sens. Tim Kaine and Mark Warner did as well.

McConnell, first elected to the Senate in 1984, has served as minority leader since 2007. The GOP takeover delivered him a personal career goal to serve as majority leader. He is the second Kentucky senator elected to the post. Former Kentucky Democratic Sen. Alben Barkley served as majority leader before becoming vice president under President Harry Truman, and he briefly considered a presidential run. McConnell is not known to harbor ambitions beyond the Senate chamber.

Across the Capitol on Thursday, House Republicans re-elected House Speaker John Boehner, R-Ohio, who will need to be approved by the full U.S. House on the first day of the new Congress, as required by the Constitution. Majority Leader Kevin McCarthy, R-Calif., and Majority Whip Steve Scalise, R-La., were also re-elected to their leadership posts.

House Democrats will hold leadership elections next week. House Minority Leader Nancy Pelosi, D-Calif., is seeking re-election unopposed. Pelosi took issue Thursday with a question about whether she would consider stepping down.

"It is just interesting as a woman to see how many times that question is asked of a woman and how many times that question is never asked of Mitch McConnell," said Pelosi, 74, about McConnell, 72, noting that the Kentucky Republican oversaw losses in his chamber for three elections in a row. "I'm here as long as my members want me to be here, as long as there's a reason to be here. I'm not here on a schedule, on anything except a mission to get a job done."

Rep. John Boehner, R-Ohio, got the approval from fellow House Republicans on Thursday to remain speaker in the next Congress, where the GOP will have an expanded majority.(Photo: Chip Somodevilla, Getty Images)